Inverted Hit n Miss engine

cfellows · Mar 28, 2012

These are pictures of an inverted hit n miss engine I completed almost a year ago. The engine was designed and built to run on compressed air, and while it runs good, I decided it would be more fun and more exciting if it was converted over to internal combustion.

Currently the engine has a bore and stroke of 1" x 1.5". I plan to make a new cylinder with a bore of 1.25", leaving the stroke at 1.5". I'll also make a new, thicker head and a shorter connecting rod to reduce the compression ratio to around 5:1. New intake valve assembly, new exhaust valve assembly, simple needle valve fuel mixer, new cam, ignition, 10mm spark plug and few other odds and ends should do it. Stay tuned...

AussieJimG · Mar 28, 2012

Looks like a good project.

I do like your projects Chuck and I will be watching all the way (and maybe commenting as well).

Jim

smfr · Mar 28, 2012

Wow, Chuck, you're bringing out all the old engines now, and they are all beauties!

crab · Mar 28, 2012

I'll be tuned in Chuck.
Bill

cfellows · Mar 30, 2012

At the last minute, I decided to leave the bore size at 1". I wasn't sure the crank disk and crankshaft could take the additional power from a 1.25" bore and I figured I might as well use as much of the existing engine as I could.

So here is the original cylinder sitting on the head.

And here is a picture of the bottom of the head. Socket head cap screws are used up from the bottom to hold the cylinder in place. A socket threaded to accept the spark plug will be silver soldered into the center hole. The spark plug will be on the bottom of the head and will not be visible. I'm hoping I don't have fouling problems from this arrangement.

Here is the head from the top, cylinder side. I cut a deep recess in the middle to lower the compression ratio. This should bring it down to 6:1 or so. The recessed holes on the outside corners accept socket head cap screws which hold the cylinder/head assembly to the engine base.

I got roped into helping SWMBO paint the spare bedroom so may not have any updates for a couple of days (1 day to paint and a second day to recuperate!) :'(

Chuck

AussieJimG · Mar 30, 2012

You could try Mr Bean's method: [ame]http://www.youtube.com/watch?v=T9MAmWnOznI[/ame]

Jim

compspecial · Mar 30, 2012

Hi Chuck, your energy and quality of your work is amazing, I find this conversion to I.C. very interesting. Hope you get your domestic duties over with soon.

Stew

Ken I · Mar 30, 2012

Hi Chuck, just signing in for the ride.

Ken

cfellows · Mar 31, 2012

Well, my efforts at silver soldering a brass plug into the head to accept the spark plug were less than successful. :-[ Couldn't get the solder to melt and I overheated the brass plug, partially melting it. I think I will now remake the head all in one piece.

Don1966 · Mar 31, 2012

Hi Chucking I want to go on this ride too. That's a nice engine I never seen a conversion like that before. I have also done what you did with the silver soldering i kind of get the jitters when it comes to that.

Regards Don

Don1966 · Mar 31, 2012

Sorry about misspelling your name Chuck this dog gone IPAD spells like it wants to. I didn't see it till after I posted it.

Don

cfellows · Mar 31, 2012

Don1966 said:
Sorry about misspelling your name Chuck this dog gone IPAD spells like it wants to. I didn't see it till after I posted it.

Don

Don't you just love the iPad completing your words for you? Most of the time it does pretty good, but sometimes, it really misses the boat!

Chuck

Don1966 · Mar 31, 2012

Yea I do, but sometimes it just does what it wants. My wife is already wanting the new IPAD. I use mine for work and I am at work now. I use it mostly for manuals and drawings and I can connect to my office and home computer to retreive things I need. There are also plenty of reference APP's that make my job easier.

Don

cfellows · Apr 1, 2012

You'd think I'd have learned by now that painting a room is always followed by hanging pictures, rearranging furniture and washing windows followed by a general house cleaning. My part of the labor includes hanging pictures (usually 2 or 3 times each), moving heavy furniture (usually 2 or 3 times each), washing windows (usually at least twice), and vacuuming the house.

But I did manage to squeeze in a bit of garage time to work on the new head for my engine. I decided to break into my jealously guarded collection of brass for the project. Here's a few pictures.

Here's the bottom and top, respectively, after the first set of operations. The spark plug will go into the center from the bottom...

Next I decided to make the head a little more organic, i.e., curvey...

And the finished product...

Still have a little filing and polishing to to do and drill the holes for the intake and the exhaust.

Chuck

coopertje · Apr 1, 2012

Nice work Chuck! As many others like your projects and work a lot :bow:

Related to the head, would it not have been more easy when you first drilled the holes for in and outlet and then make the nice rounded shape? I find it more easy to locate them on a square piece then on a round....

Looking forward to your progress, regards Jeroen

cfellows · Apr 1, 2012

coopertje said:
Nice work Chuck! As many others like your projects and work a lot :bow:

Related to the head, would it not have been more easy when you first drilled the holes for in and outlet and then make the nice rounded shape? I find it more easy to locate them on a square piece then on a round....

Looking forward to your progress, regards Jeroen

Thanks, Jeroen. You're right about the holes. One of my big failings is I tend to jump first and think later. It's not uncommon for me to make things harder for myself by being impetuous. But, it also keeps things more interesting! :-[

Chuck

metalmad · Apr 1, 2012

Hi Chuck
I love that fixture plate on your R/T
Looks like a must have to me :bow:
Pete

cfellows · Apr 1, 2012

metalmad said:
Hi Chuck
I love that fixture plate on your R/T
Looks like a must have to me :bow:
Pete

Thanks, Pete, but that's not a fixture plate... that is the rotary table.

[ame=http://www.youtube.com/watch?v=am5774rnjtU]http://www.youtube.com/watch?v=am5774rnjtU[/ame]

Chuck

Troutsqueezer · Apr 1, 2012

Chuck, the plain fact is: You do good work. I like the curves in that piece.

I've decided to make all my engines from here on out with extra pizazz. I care as much about the looks as the operation. After all, I spend more looking at them than running them. This one should look good up there on the shelf.

cfellows · Apr 1, 2012

Thanks, Trout. A few months ago I had the same revelation... my models spend more time on the shelf than in the shop running, so why not make them pretty. Been trying to follow that mantra ever since.

Chuck

Inverted Hit n Miss engine

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